Version July 2025
Please read the Disclaimer at the end of this page.
What is a quadruple test? —
A quadruple test ("quad test") measures the amounts of 4 substances in your blood:
●Alpha-fetoprotein ("AFP")
●Unconjugated estriol ("uE3")
●Human chorionic gonadotropin ("hCG")
●Inhibin A
These are produced by your fetus (developing baby) during pregnancy. The substances enter your blood through the placenta. (The placenta is the organ that forms between you and your baby during pregnancy.)
Doctors use a quad test to help figure out if a fetus has an increased risk of having certain disorders, such as:
●Down syndrome – This is a condition that happens when a person is born with an extra chromosome. Chromosomes are tiny parts of cells that carry the plans that make our bodies the way they are.
●Certain other genetic disorders – These include trisomy 18, also called "Edwards syndrome." It is less common than Down syndrome.
Why might I get a quad test? —
Your doctor might order this test if you are pregnant and:
●You want to know how likely your fetus is to have Down syndrome.
●Your first prenatal appointment is during your second trimester.
This test is usually done between 15 and 18 weeks of pregnancy. Some people have it as late as 22 weeks.
How do I prepare for a quad test? —
You need to get a "blood draw." Your doctor or nurse will tell you where to go for this.
It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.
What happens during a blood draw? —
A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.
Tell the person who takes your blood:
●If you take "blood thinner" medicines or if you have a bleeding problem – They will make sure your bleeding is under control before you leave.
●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.
●If you have a preferred arm to use
Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.
What do my results mean? —
Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.
If your quad test shows any abnormal results, your doctor or nurse will talk to you about what to do next. It might also help to talk with an expert called a "genetic counselor." If the test results show your fetus has a high chance of having a disorder, you can choose to have a "diagnostic" test to find out for sure.
Patient education: Testing for Down syndrome during pregnancy (The Basics)
Patient education: Down syndrome (The Basics)
Patient education: Cell-free DNA prenatal screening (The Basics)
Patient education: Maternal serum alpha-fetoprotein test (The Basics)
Patient education: Amniocentesis (The Basics)
Patient education: Chorionic villus sampling (The Basics)
Patient education: Should I have a screening test for Down syndrome during pregnancy? (Beyond the Basics)
Patient education: Down syndrome (Beyond the Basics)
Patient education: Amniocentesis (Beyond the Basics)
Patient education: Chorionic villus sampling (Beyond the Basics)
